Marine Mammal Scientific Support Research Programme

Three specific research Themes (Marine Renewables, Harbour Seal Decline and Seals and Salmon Interactions) have been prioritised.

Theme 1 – Marine Renewable Energy (MRE)

Uncertainty over the nature of any impacts highlights the need to evaluate potential interactions between seals and cetaceans and various tidal, wind and wave devices.  The investigation of suitable mitigation measures is also a priority. There is a need to develop robust assessment and monitoring methods and management approaches for marine mammals to minimise any potential adverse effects of renewable energy devices. This work aims to build upon previous work funded by the Scottish Government. The tasks in this theme include:

  • Fine scale marine mammal behaviour around tidal energy devices
  • Harbour seal movement modelling
  • Estimating collision risk using available information
  • Individual consequences of tidal turbine impacts

Theme 2 – Harbour Seal Decline

Two harbour seal decline workshops (August 2012 and April 2014) discussed in some detail the various factors that might be involved in the decline.  A number were ruled out, such as pollutants, Phocine Distemper Virus (PDV) and bycatch. A topic sheet is available to download and offers further information on this issue. This left competition with grey seals as the most likely cause and this is now being followed up and will be addressed under this research theme:

  • Harbour seal decline factors
  • Harbour seal decline – vital rates and drivers
  • Harbour seal management and mitigation

In addition, recent evidence of predation by grey seals as a potential driver of harbour seal population trends has now been incorporated within this study.

Theme 3 – Seals and Salmon Interactions

The overall aim of this theme is to identify and prioritise focused research activity with the purpose of understanding the interactions between seals and salmon fisheries and how non-lethal measures can improve effective management of this interaction. In order to inform policy development and delivery, it is paramount that there is a sound understanding and evidence base of the complex interactions between seal and salmon fisheries so that non-lethal measures can be recommended that can assist in addressing highly sensitive concerns regarding the lethal removal of seals.

The objectives of this study is therefore to investigate the effectiveness of acoustic deterrent devices (ADDs) and the modification of salmon nets to mitigate the effects of seals on these fisheries; to collect seal carcases for dietary analysis and provide scientific support to the district salmon fishery boards (DSFBs).

Completed reports

The following reports have been completed under the above project:

Current state of knowledge of effects of offshore renewable energy generation devices on marine mammals and research requirements (MR1 and MR2)

Methods for tracking the fine scale underwater movements of marine mammals around marine tidal devices (MR3) 

Grey and harbour seal usage maps (MR5)

Current state of knowledge of the extent, cause and population effects of unusual mortality events in Scottish seals (USD1 and USD6)

Review of the status, trends and potential causes for the decline in abundance of harbour seals around the coast of Scotland (CSD1)

Workshop report on decline in the abundance of harbour seals around the coast of Scotland and discussion of mitigation and management measures (CSD1 and CSD2)

Testing The Hypothetical Link Between Shipping And Unexplained Seal Deaths (USD2)

Harbour seal behaviour in high tidal areas (Kylerhea)

Grey and harbour seal density maps

More information about related reports can be found in the Offshore Renewables web section.